There are many ways of delivering active pharmaceutical agents to a patient body depending on the type of drug and the disorder to treat or prevent. A common administration protocol is oral delivery of oral formulations, such as tablets, capsules and lozenges. In this administration route, the tablet is swallowed for release of the agent in the intestine.
A problem associated with oral delivery to the stomach is that many drugs may be degraded during the passage through the acid environment of the gastrointestinal system. When the agent has entered the intestine it is taken up into the blood stream via the portal vein in the liver, where a large portion of the active agent is typically metabolized into inactive chemicals by the enzymes of the so-called first-pass metabolism.
These factors result in a significant delay before a positive therapeutic effect can be noted, leading to a risk of gastrointestinal side effects augmented by the need of administering considerably higher amount of the active agent than would be needed by, for instance, a direct injection of a drug solution into the vein.
WO 2007/104573 discloses the delivery of the active agent nicotine to the oral cavity of a patient in the form of a snuff product. The snuff product comprises a semi-permeable snuff pouch enclosing small particles of microcrystalline cellulose having the nicotine sorbed to the surface of the cellulose particles. When being placed between the lip and the teeth of the patient, the onset of the nicotine effect is very rapid, typically within 1 to 2 minutes after application of the snuff pouch.
WO 2005/023227 discloses nicotine-containing pharmaceutical compositions wherein nicotine is absorbed into and/or adsorbed onto cellulose of non-seed organism origin, especially cellulose from algae, bacteria and/or fungi. A vast amount of products comprising the pharmaceutical compositions are given in the document, including chewing gums, mouth sprays, nasal sprays, inhaling devices, tablets, lozenges, buccal sachets, transdermal patches and powders.